Polycondensation-Involved Melanin-like Polymers for Enhanced Solar Energy Utilization

Polydopamine(PDA) and poly(5,6-dihydroxyindole) (PDHI), both typicalrepresentatives of melanin-like polymers, are emerging as promisingkinds of photothermal functional materials with a similar polymericstructure. However, the chaos of the microstructure formed by freeradical polymerization of monomers still hinders the efficient regulationof their photothermal performances. Herein, we introduced condensationpolymerization between aldehydes and the 5,6-dihydroxyindole (DHI)monomer during the free radical polymerization process to constructmore D-A pairs, which can regulate the energy structures andreduce the optical band gaps within the macromolecules. In this way,a series of PDHI nanoparticles (NPs) with enhanced light absorptionof visible light and photothermal properties were successfully preparedand were used for solar power generation and water desalination with91.8% evaporation efficiency. It was believed that this work couldprovide new opportunities for the structure-function tailoringof bioinspired materials and further expand their applications forhigh-efficiency solar energy utilization.